The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
Internal combustion engines combust a mixture of air and fuel to generate torque. The fuel of the air/fuel mixture may be a combination of liquid fuel and vapor fuel. A fuel system is used to supply liquid fuel and vapor fuel to the engine. A fuel injector provides the engine with liquid fuel drawn from a fuel tank. The fuel system may include an evaporative emissions (EVAP) system that provides the engine with fuel vapor drawn from a canister.
Generally, liquid fuel is contained within the fuel tank. In some circumstances, the liquid fuel may vaporize and form fuel vapor. The canister stores the fuel vapor. The EVAP system includes a purge valve and a vent valve. Operation of the engine causes a vacuum (low pressure relative to atmospheric pressure) to form within an intake manifold of the engine. The vacuum within the intake manifold and actuation of the purge and vent valves allows the fuel vapor to be drawn into the intake manifold, thereby purging the fuel vapor from the canister to the intake manifold.